One method for preheating glass batch involves feeding cold particulate glass batch raw materials into one end of a rotating heat-transfer drum, and feeding hot media of larger particle size than the batch particles into the other end of the heat transfer drum. The glass batch moves in direct and immediate physical contact with the heated media, with the batch flowing from the cold end to the hot end of the drum and the media flowing from the hot end to the cold end of the drum. The heated particulate batch is removed from the hot end of the drum, and the cooled media is removed from the cold end of the drum. Preferably, the heat transfer media is of a durable material and can be comprised of glass batch agglomerates, glass, ceramic material, steel, stainless steel, aluminum, or gravel. The media can be spherical in shape, and a useable example of such media is spherical ceramic balls. The media can be heated with an external burner or preferably heated by direct contact with exhaust gases from a glass melting furnace.
A problem with such a preheating apparatus and method is that the cold balls exiting the heat transfer drum carry some of the particulate glass batch with them. This is undesirable because the particulate glass batch can melt and foul the heating apparatus for reheating the balls prior to their reintroduction into the heat transfer drum. There is a need for separating particulate batch material from the heat transfer media as the heat transfer media is discharged from the heat transfer drum.